wavheader.js ➔ getDwChannelMask_ - Code Metrics - Inspection of "Solve mixed responsibilities between WaveFile, wav..." - rochars/wavefile - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Branch — v8.x (3f6847)

by Rafael S.

created 2018-07-10 22:10 UTC

wavheader.js ➔ getDwChannelMask_ B

↳ Parent: lib/wavheader.js

Complexity

Conditions	6
Paths	6

Size

Total Lines	21
Code Lines	13

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	6
eloc	13
c	1
b	0
f	0
nc	6
nop	1
dl	0
loc	21
rs	8.6666

/*
 * Copyright (c) 2018 Rafael da Silva Rocha.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

/**
 * @fileoverview A tool to create wav file headers.
 * @see https://github.com/rochars/wavefile
 */

/**
 * Audio formats.
 * Formats not listed here will be set to 65534,
 * the code for WAVE_FORMAT_EXTENSIBLE
 * @enum {number}
 * @private
 */
export const AUDIO_FORMATS = {
  '4': 17,
  '8': 1,
  '8a': 6,
  '8m': 7,
  '16': 1,
  '24': 1,
  '32': 1,
  '32f': 3,
  '64': 3
};

/**
 * Return the header for a wav file.
 * @param {string} bitDepthCode The audio bit depth
 * @param {number} numChannels The number of channels
 * @param {number} sampleRate The sample rate.
 * @param {number} numBytes The number of bytes each sample use.
 * @param {number} samplesLength The length of the samples in bytes.
 * @param {!Object} options The extra options, like container defintion.
 * @private
 */
export function wavHeader(bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
  let header = {};

  if (bitDepthCode == '4') {
    header = createADPCMHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);

  } else if (bitDepthCode == '8a' || bitDepthCode == '8m') {
    header = createALawMulawHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);

  } else if(Object.keys(AUDIO_FORMATS).indexOf(bitDepthCode) == -1 ||
      numChannels > 2) {
    header = createExtensibleHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);

  } else {
    header = createPCMHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);      
  }
  return header;
}

/**
 * Validate the header of the file.
 * @throws {Error} If any property of the object appears invalid.
 * @private
 */
export function validateHeader_(header) {
  validateBitDepth_(header);
  validateNumChannels_(header);
  validateSampleRate_(header);
}

/**
 * Validate the bit depth.
 * @return {boolean} True is the bit depth is valid.
 * @throws {Error} If bit depth is invalid.
 * @private
 */
function validateBitDepth_(header) {
  if (!AUDIO_FORMATS[header.bitDepth]) {
    if (parseInt(header.bitDepth, 10) > 8 &&
        parseInt(header.bitDepth, 10) < 54) {
      return true;
    }
    throw new Error('Invalid bit depth.');
  }
  return true;
}

/**
 * Validate the number of channels.
 * @return {boolean} True is the number of channels is valid.
 * @throws {Error} If the number of channels is invalid.
 * @private
 */
function validateNumChannels_(header) {
  /** @type {number} */
  let blockAlign = header.fmt.numChannels * header.fmt.bitsPerSample / 8;
  if (header.fmt.numChannels < 1 || blockAlign > 65535) {
    throw new Error('Invalid number of channels.');
  }
  return true;
}

/**
 * Validate the sample rate value.
 * @return {boolean} True is the sample rate is valid.
 * @throws {Error} If the sample rate is invalid.
 * @private
 */
function validateSampleRate_(header) {
  /** @type {number} */
  let byteRate = header.fmt.numChannels *
    (header.fmt.bitsPerSample / 8) * header.fmt.sampleRate;
  if (header.fmt.sampleRate < 1 || byteRate > 4294967295) {
    throw new Error('Invalid sample rate.');
  }
  return true;
}

/**
 * Create the header of a linear PCM wave file.
 * @param {string} bitDepthCode The audio bit depth
 * @param {number} numChannels The number of channels
 * @param {number} sampleRate The sample rate.
 * @param {number} numBytes The number of bytes each sample use.
 * @param {number} samplesLength The length of the samples in bytes.
 * @param {!Object} options The extra options, like container defintion.
 * @private
 */
function createPCMHeader_(bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
  return {
    container: options.container,
    chunkSize: 36 + samplesLength,
    format: 'WAVE',
    bitDepth: bitDepthCode,
    fmt: {
      chunkId: 'fmt ',
      chunkSize: 16,
      audioFormat: AUDIO_FORMATS[bitDepthCode] ? AUDIO_FORMATS[bitDepthCode] : 65534,
      numChannels: numChannels,
      sampleRate: sampleRate,
      byteRate: (numChannels * numBytes) * sampleRate,
      blockAlign: numChannels * numBytes,
      bitsPerSample: parseInt(bitDepthCode, 10),
      cbSize: 0,
      validBitsPerSample: 0,
      dwChannelMask: 0,
      subformat: []
    }
  };
}

/**
 * Create the header of a ADPCM wave file.
 * @param {string} bitDepthCode The audio bit depth
 * @param {number} numChannels The number of channels
 * @param {number} sampleRate The sample rate.
 * @param {number} numBytes The number of bytes each sample use.
 * @param {number} samplesLength The length of the samples in bytes.
 * @param {!Object} options The extra options, like container defintion.
 * @private
 */
function createADPCMHeader_(bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
  let header = createPCMHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
  header.chunkSize = 40 + samplesLength;
  header.fmt.chunkSize = 20;
  header.fmt.byteRate = 4055;
  header.fmt.blockAlign = 256;
  header.fmt.bitsPerSample = 4;
  header.fmt.cbSize = 2;
  header.fmt.validBitsPerSample = 505;
  header.fact = {
    chunkId: 'fact',
    chunkSize: 4,
    dwSampleLength: samplesLength * 2
  };
  return header;
}

/**
 * Create the header of WAVE_FORMAT_EXTENSIBLE file.
 * @param {string} bitDepthCode The audio bit depth
 * @param {number} numChannels The number of channels
 * @param {number} sampleRate The sample rate.
 * @param {number} numBytes The number of bytes each sample use.
 * @param {number} samplesLength The length of the samples in bytes.
 * @param {!Object} options The extra options, like container defintion.
 * @private
 */
function createExtensibleHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
  let header = createPCMHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
  header.chunkSize = 36 + 24 + samplesLength;
  header.fmt.chunkSize = 40;
  header.fmt.bitsPerSample = ((parseInt(bitDepthCode, 10) - 1) | 7) + 1;
  header.fmt.cbSize = 22;
  header.fmt.validBitsPerSample = parseInt(bitDepthCode, 10);
  header.fmt.dwChannelMask = getDwChannelMask_(numChannels);
  // subformat 128-bit GUID as 4 32-bit values
  // only supports uncompressed integer PCM samples
  header.fmt.subformat = [1, 1048576, 2852126848, 1905997824];
  return header;
}

/**
 * Create the header of mu-Law and A-Law wave files.
 * @param {string} bitDepthCode The audio bit depth
 * @param {number} numChannels The number of channels
 * @param {number} sampleRate The sample rate.
 * @param {number} numBytes The number of bytes each sample use.
 * @param {number} samplesLength The length of the samples in bytes.
 * @param {!Object} options The extra options, like container defintion.
 * @private
 */
function createALawMulawHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
  let header = createPCMHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
  header.chunkSize = 40 + samplesLength;
  header.fmt.chunkSize = 20;
  header.fmt.cbSize = 2;
  header.fmt.validBitsPerSample = 8;
  header.fact = {
    chunkId: 'fact',
    chunkSize: 4,
    dwSampleLength: samplesLength
  };
  return header;
}

/**
 * Get the value for dwChannelMask according to the number of channels.
 * @return {number} the dwChannelMask value.
 * @private
 */
function getDwChannelMask_(numChannels) {
  /** @type {number} */
  let dwChannelMask = 0;
  // mono = FC
  if (numChannels === 1) {
    dwChannelMask = 0x4;
  // stereo = FL, FR
  } else if (numChannels === 2) {
    dwChannelMask = 0x3;
  // quad = FL, FR, BL, BR
  } else if (numChannels === 4) {
    dwChannelMask = 0x33;
  // 5.1 = FL, FR, FC, LF, BL, BR
  } else if (numChannels === 6) {
    dwChannelMask = 0x3F;
  // 7.1 = FL, FR, FC, LF, BL, BR, SL, SR
  } else if (numChannels === 8) {
    dwChannelMask = 0x63F;
  }
  return dwChannelMask;
}


1			/*
2			* Copyright (c) 2018 Rafael da Silva Rocha.
3			*
4			* Permission is hereby granted, free of charge, to any person obtaining
5			* a copy of this software and associated documentation files (the
6			* "Software"), to deal in the Software without restriction, including
7			* without limitation the rights to use, copy, modify, merge, publish,
8			* distribute, sublicense, and/or sell copies of the Software, and to
9			* permit persons to whom the Software is furnished to do so, subject to
10			* the following conditions:
11			*
12			* The above copyright notice and this permission notice shall be
13			* included in all copies or substantial portions of the Software.
14			*
15			* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16			* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17			* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18			* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
19			* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
20			* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21			* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22			*
23			*/
24
25			/**
26			* @fileoverview A tool to create wav file headers.
27			* @see https://github.com/rochars/wavefile
28			*/
29
30			/**
31			* Audio formats.
32			* Formats not listed here will be set to 65534,
33			* the code for WAVE_FORMAT_EXTENSIBLE
34			* @enum {number}
35			* @private
36			*/
37			export const AUDIO_FORMATS = {
38			'4': 17,
39			'8': 1,
40			'8a': 6,
41			'8m': 7,
42			'16': 1,
43			'24': 1,
44			'32': 1,
45			'32f': 3,
46			'64': 3
47			};
48
49			/**
50			* Return the header for a wav file.
51			* @param {string} bitDepthCode The audio bit depth
52			* @param {number} numChannels The number of channels
53			* @param {number} sampleRate The sample rate.
54			* @param {number} numBytes The number of bytes each sample use.
55			* @param {number} samplesLength The length of the samples in bytes.
56			* @param {!Object} options The extra options, like container defintion.
57			* @private
58			*/
59			export function wavHeader(bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
60			let header = {};
			0 ignored issues – show Unused Code introduced 2018-07-10 07:50 UTC by Report Bug Copy Issue Report The assignment to variable `header` seems to be never used. Consider removing it. Loading history...
61			if (bitDepthCode == '4') {
62			header = createADPCMHeader_(
63			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
64
65			} else if (bitDepthCode == '8a' \|\| bitDepthCode == '8m') {
66			header = createALawMulawHeader_(
67			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
68
69			} else if(Object.keys(AUDIO_FORMATS).indexOf(bitDepthCode) == -1 \|\|
70			numChannels > 2) {
71			header = createExtensibleHeader_(
72			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
73
74			} else {
75			header = createPCMHeader_(
76			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
77			}
78			return header;
79			}
80
81			/**
82			* Validate the header of the file.
83			* @throws {Error} If any property of the object appears invalid.
84			* @private
85			*/
86			export function validateHeader_(header) {
87			validateBitDepth_(header);
88			validateNumChannels_(header);
89			validateSampleRate_(header);
90			}
91
92			/**
93			* Validate the bit depth.
94			* @return {boolean} True is the bit depth is valid.
95			* @throws {Error} If bit depth is invalid.
96			* @private
97			*/
98			function validateBitDepth_(header) {
99			if (!AUDIO_FORMATS[header.bitDepth]) {
100			if (parseInt(header.bitDepth, 10) > 8 &&
101			parseInt(header.bitDepth, 10) < 54) {
102			return true;
103			}
104			throw new Error('Invalid bit depth.');
105			}
106			return true;
107			}
108
109			/**
110			* Validate the number of channels.
111			* @return {boolean} True is the number of channels is valid.
112			* @throws {Error} If the number of channels is invalid.
113			* @private
114			*/
115			function validateNumChannels_(header) {
116			/** @type {number} */
117			let blockAlign = header.fmt.numChannels * header.fmt.bitsPerSample / 8;
118			if (header.fmt.numChannels < 1 \|\| blockAlign > 65535) {
119			throw new Error('Invalid number of channels.');
120			}
121			return true;
122			}
123
124			/**
125			* Validate the sample rate value.
126			* @return {boolean} True is the sample rate is valid.
127			* @throws {Error} If the sample rate is invalid.
128			* @private
129			*/
130			function validateSampleRate_(header) {
131			/** @type {number} */
132			let byteRate = header.fmt.numChannels *
133			(header.fmt.bitsPerSample / 8) * header.fmt.sampleRate;
134			if (header.fmt.sampleRate < 1 \|\| byteRate > 4294967295) {
135			throw new Error('Invalid sample rate.');
136			}
137			return true;
138			}
139
140			/**
141			* Create the header of a linear PCM wave file.
142			* @param {string} bitDepthCode The audio bit depth
143			* @param {number} numChannels The number of channels
144			* @param {number} sampleRate The sample rate.
145			* @param {number} numBytes The number of bytes each sample use.
146			* @param {number} samplesLength The length of the samples in bytes.
147			* @param {!Object} options The extra options, like container defintion.
148			* @private
149			*/
150			function createPCMHeader_(bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
151			return {
152			container: options.container,
153			chunkSize: 36 + samplesLength,
154			format: 'WAVE',
155			bitDepth: bitDepthCode,
156			fmt: {
157			chunkId: 'fmt ',
158			chunkSize: 16,
159			audioFormat: AUDIO_FORMATS[bitDepthCode] ? AUDIO_FORMATS[bitDepthCode] : 65534,
160			numChannels: numChannels,
161			sampleRate: sampleRate,
162			byteRate: (numChannels * numBytes) * sampleRate,
163			blockAlign: numChannels * numBytes,
164			bitsPerSample: parseInt(bitDepthCode, 10),
165			cbSize: 0,
166			validBitsPerSample: 0,
167			dwChannelMask: 0,
168			subformat: []
169			}
170			};
171			}
172
173			/**
174			* Create the header of a ADPCM wave file.
175			* @param {string} bitDepthCode The audio bit depth
176			* @param {number} numChannels The number of channels
177			* @param {number} sampleRate The sample rate.
178			* @param {number} numBytes The number of bytes each sample use.
179			* @param {number} samplesLength The length of the samples in bytes.
180			* @param {!Object} options The extra options, like container defintion.
181			* @private
182			*/
183			function createADPCMHeader_(bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
184			let header = createPCMHeader_(
185			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
186			header.chunkSize = 40 + samplesLength;
187			header.fmt.chunkSize = 20;
188			header.fmt.byteRate = 4055;
189			header.fmt.blockAlign = 256;
190			header.fmt.bitsPerSample = 4;
191			header.fmt.cbSize = 2;
192			header.fmt.validBitsPerSample = 505;
193			header.fact = {
194			chunkId: 'fact',
195			chunkSize: 4,
196			dwSampleLength: samplesLength * 2
197			};
198			return header;
199			}
200
201			/**
202			* Create the header of WAVE_FORMAT_EXTENSIBLE file.
203			* @param {string} bitDepthCode The audio bit depth
204			* @param {number} numChannels The number of channels
205			* @param {number} sampleRate The sample rate.
206			* @param {number} numBytes The number of bytes each sample use.
207			* @param {number} samplesLength The length of the samples in bytes.
208			* @param {!Object} options The extra options, like container defintion.
209			* @private
210			*/
211			function createExtensibleHeader_(
212			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
213			let header = createPCMHeader_(
214			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
215			header.chunkSize = 36 + 24 + samplesLength;
216			header.fmt.chunkSize = 40;
217			header.fmt.bitsPerSample = ((parseInt(bitDepthCode, 10) - 1) \| 7) + 1;
218			header.fmt.cbSize = 22;
219			header.fmt.validBitsPerSample = parseInt(bitDepthCode, 10);
220			header.fmt.dwChannelMask = getDwChannelMask_(numChannels);
221			// subformat 128-bit GUID as 4 32-bit values
222			// only supports uncompressed integer PCM samples
223			header.fmt.subformat = [1, 1048576, 2852126848, 1905997824];
224			return header;
225			}
226
227			/**
228			* Create the header of mu-Law and A-Law wave files.
229			* @param {string} bitDepthCode The audio bit depth
230			* @param {number} numChannels The number of channels
231			* @param {number} sampleRate The sample rate.
232			* @param {number} numBytes The number of bytes each sample use.
233			* @param {number} samplesLength The length of the samples in bytes.
234			* @param {!Object} options The extra options, like container defintion.
235			* @private
236			*/
237			function createALawMulawHeader_(
238			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
239			let header = createPCMHeader_(
240			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
241			header.chunkSize = 40 + samplesLength;
242			header.fmt.chunkSize = 20;
243			header.fmt.cbSize = 2;
244			header.fmt.validBitsPerSample = 8;
245			header.fact = {
246			chunkId: 'fact',
247			chunkSize: 4,
248			dwSampleLength: samplesLength
249			};
250			return header;
251			}
252
253			/**
254			* Get the value for dwChannelMask according to the number of channels.
255			* @return {number} the dwChannelMask value.
256			* @private
257			*/
258			function getDwChannelMask_(numChannels) {
259			/** @type {number} */
260			let dwChannelMask = 0;
261			// mono = FC
262			if (numChannels === 1) {
263			dwChannelMask = 0x4;
264			// stereo = FL, FR
265			} else if (numChannels === 2) {
266			dwChannelMask = 0x3;
267			// quad = FL, FR, BL, BR
268			} else if (numChannels === 4) {
269			dwChannelMask = 0x33;
270			// 5.1 = FL, FR, FC, LF, BL, BR
271			} else if (numChannels === 6) {
272			dwChannelMask = 0x3F;
273			// 7.1 = FL, FR, FC, LF, BL, BR, SL, SR
274			} else if (numChannels === 8) {
275			dwChannelMask = 0x63F;
276			}
277			return dwChannelMask;
278			}
279

rochars / wavefile

Branch — v8.x (3f6847)

wavheader.js ➔ getDwChannelMask_ B

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